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548. [func] The lexer now ungets tokens more correctly.

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This commit is contained in:
Brian Wellington
2000-11-09 02:23:40 +00:00
parent a90dcd1f19
commit 066faef119
2 changed files with 84 additions and 43 deletions
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2
CHANGES
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@@ -1,4 +1,4 @@
547. [none]
548. [func] The lexer now ungets tokens more correctly.
546. [func] Option 'lame-ttl' is now implemented.

125
lib/isc/lex.c
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@@ -15,7 +15,7 @@
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: lex.c,v 1.40 2000/11/08 01:55:29 bwelling Exp $ */
/* $Id: lex.c,v 1.41 2000/11/09 02:23:40 bwelling Exp $ */
#include <config.h>
@@ -36,10 +36,7 @@ typedef struct inputsource {
isc_boolean_t is_file;
isc_boolean_t need_close;
isc_boolean_t at_eof;
isc_boolean_t have_token;
isc_token_t token;
unsigned int char_count;
int chars[2];
isc_buffer_t * pushback;
void * input;
char * name;
unsigned long line;
@@ -189,6 +186,7 @@ new_source(isc_lex_t *lex, isc_boolean_t is_file, isc_boolean_t need_close,
void *input, const char *name)
{
inputsource *source;
isc_result_t result;
source = isc_mem_get(lex->mctx, sizeof *source);
if (source == NULL)
@@ -197,16 +195,20 @@ new_source(isc_lex_t *lex, isc_boolean_t is_file, isc_boolean_t need_close,
source->is_file = is_file;
source->need_close = need_close;
source->at_eof = ISC_FALSE;
source->have_token = ISC_FALSE;
source->token.type = isc_tokentype_unknown;
source->token.value.as_pointer = NULL;
source->char_count = 0;
source->input = input;
source->name = isc_mem_strdup(lex->mctx, name);
if (source->name == NULL) {
isc_mem_put(lex->mctx, source, sizeof *source);
return (ISC_R_NOMEMORY);
}
source->pushback = NULL;
result = isc_buffer_allocate(lex->mctx, &source->pushback,
lex->max_token);
if (result != ISC_R_SUCCESS) {
isc_mem_free(lex->mctx, source->name);
isc_mem_put(lex->mctx, source, sizeof *source);
return (result);
}
source->line = 1;
ISC_LIST_PREPENDUNSAFE(lex->sources, source, link);
@@ -293,6 +295,7 @@ isc_lex_close(isc_lex_t *lex) {
fclose((FILE *)(source->input));
}
isc_mem_free(lex->mctx, source->name);
isc_buffer_free(&source->pushback);
isc_mem_put(lex->mctx, source, sizeof *source);
return (ISC_R_SUCCESS);
@@ -314,12 +317,41 @@ typedef enum {
static void
pushback(inputsource *source, int c) {
INSIST(source->char_count < 2);
source->chars[source->char_count++] = c;
REQUIRE(source->pushback->current > 0);
source->pushback->current--;
if (c == '\n')
source->line--;
}
static void
unpushback(inputsource *source) {
isc_buffer_subtract(source->pushback, 1);
}
static isc_result_t
pushandgrow(isc_lex_t *lex, inputsource *source, int c) {
if (isc_buffer_availablelength(source->pushback) == 0) {
isc_buffer_t *tbuf = NULL;
unsigned int oldlen;
isc_region_t used;
isc_result_t result;
oldlen = isc_buffer_length(source->pushback);
result = isc_buffer_allocate(lex->mctx, &tbuf, oldlen * 2);
if (result != ISC_R_SUCCESS)
return (result);
isc_buffer_usedregion(source->pushback, &used);
result = isc_buffer_copyregion(tbuf, &used);
INSIST(result == ISC_R_SUCCESS);
isc_buffer_free(&source->pushback);
source->pushback = tbuf;
}
isc_buffer_putuint8(source->pushback, (isc_uint8_t)c);
if (c == '\n')
source->line--;
return (ISC_R_SUCCESS);
}
isc_result_t
isc_lex_gettoken(isc_lex_t *lex, unsigned int options, isc_token_t *tokenp) {
inputsource *source;
@@ -357,13 +389,9 @@ isc_lex_gettoken(isc_lex_t *lex, unsigned int options, isc_token_t *tokenp) {
if (source->result != ISC_R_SUCCESS)
return (source->result);
if (source->have_token) {
*tokenp = source->token;
source->have_token = ISC_FALSE;
return (ISC_R_SUCCESS);
}
if (source->char_count == 0 && source->at_eof) {
if (isc_buffer_remaininglength(source->pushback) == 0 &&
source->at_eof)
{
if ((options & ISC_LEXOPT_DNSMULTILINE) != 0 &&
lex->paren_count != 0)
return (ISC_R_UNBALANCED);
@@ -374,6 +402,8 @@ isc_lex_gettoken(isc_lex_t *lex, unsigned int options, isc_token_t *tokenp) {
return (ISC_R_EOF);
}
isc_buffer_compact(source->pushback);
saved_options = options;
if ((options & ISC_LEXOPT_DNSMULTILINE) != 0 && lex->paren_count > 0)
options &= ~IWSEOL;
@@ -382,35 +412,42 @@ isc_lex_gettoken(isc_lex_t *lex, unsigned int options, isc_token_t *tokenp) {
prev = NULL;
remaining = lex->max_token;
do {
if (source->char_count > 0) {
source->char_count--;
c = source->chars[source->char_count];
} else if (source->is_file) {
stream = source->input;
if (isc_buffer_remaininglength(source->pushback) == 0) {
if (source->is_file) {
stream = source->input;
#ifdef HAVE_FLOCKFILE
c = getc_unlocked(stream);
c = getc_unlocked(stream);
#else
c = getc(stream);
c = getc(stream);
#endif
if (c == EOF) {
if (ferror(stream)) {
source->result = ISC_R_IOERROR;
return (source->result);
if (c == EOF) {
if (ferror(stream)) {
source->result = ISC_R_IOERROR;
return (source->result);
}
source->at_eof = ISC_TRUE;
}
source->at_eof = ISC_TRUE;
}
} else {
buffer = source->input;
if (buffer->current == buffer->used) {
c = EOF;
source->at_eof = ISC_TRUE;
} else {
c = *((char *)buffer->base + buffer->current);
buffer->current++;
buffer = source->input;
if (buffer->current == buffer->used) {
c = EOF;
source->at_eof = ISC_TRUE;
} else {
c = *((char *)buffer->base +
buffer->current);
buffer->current++;
}
}
if (c != EOF) {
source->result = pushandgrow(lex, source, c);
if (source->result != ISC_R_SUCCESS)
return (source->result);
}
}
if (!source->at_eof)
c = isc_buffer_getuint8(source->pushback);
if (c == '\n')
source->line++;
@@ -492,6 +529,7 @@ isc_lex_gettoken(isc_lex_t *lex, unsigned int options, isc_token_t *tokenp) {
if (lex->paren_count == 0)
options =
saved_options;
unpushback(source);
}
continue;
}
@@ -574,6 +612,8 @@ isc_lex_gettoken(isc_lex_t *lex, unsigned int options, isc_token_t *tokenp) {
(c == ' ' || c == '\t' || lex->specials[c])) ||
c == '\r' || c == '\n' || c == EOF) {
pushback(source, c);
if (source->result != ISC_R_SUCCESS)
return (source->result);
tokenp->type = isc_tokentype_string;
tokenp->value.as_textregion.base = lex->data;
tokenp->value.as_textregion.length =
@@ -733,11 +773,12 @@ isc_lex_ungettoken(isc_lex_t *lex, isc_token_t *tokenp) {
REQUIRE(VALID_LEX(lex));
source = HEAD(lex->sources);
REQUIRE(source != NULL);
REQUIRE(!source->have_token);
REQUIRE(tokenp != NULL);
REQUIRE(isc_buffer_consumedlength(source->pushback) != 0);
source->token = *tokenp;
source->have_token = ISC_TRUE;
UNUSED(tokenp);
isc_buffer_first(source->pushback);
}
char *